Armature mounting assembly for a teleprinter

ABSTRACT

A plurality of self-restoring horizontally spaced apart print hammers selectively are driven lineally toward printing positions by continuously rotating impellers having equiangularly spaced radial impelling elements. Each impeller is effective through the agency of an interponent, which is selectively elevated into and then removed from the path of associated impelling elements of an impeller. Interponent elevation results from latching of the armature of an electromagnet. Transmission of impeller force to a print hammer results from striking of an elevated interponent by its impeller. The electromagnets are disposed in a pair of spaced apart banks aligned on opposite sides of the interponents, their armatures extending inwardly from said electromagnets and providing a plurality of aligned stands to which the lower ends of the interponents are returned by the springs, whereby armature control of the interponents is regained following armature unlatching.

United States Patent [191 Babler Apr. 23, 1974 ARMATURE- MOUNTING ASSEMBLY FOR A TELEPRINTER Egon S. Babler, Northbrook, Ill.

[73] Assignee: Teletype Corporation, Skokie, 111.

[22] Filed: Sept. 18, 1972 [21] Appl. No.: 292,003

[75] Inventor:

Primary Examiner--Robert E. Pulfrey Assistant Examiner-E. M. Coven Attorney, Agent, or Firm-Sherman P. Appel; John L. Landis /IO6B 106A- 5 7] ABSTRACT 'A plurality of self-restoring horizontally spaced apart print hammers selectively are driven lineally toward printing positions by continuously rotating impellers having equiangularly spaced radial impelling elements. Each impeller is effective through the agency of an interponent, which is selectively elevated into and then removed from the path of associated impelling elements of an impeller. lnterponent elevation results from latching of the armature of an electromagnet. Transmission of impeller force to a print hammer results from striking of an elevated interponent by its impeller. The electromagnets are disposed in a pair of spaced apart banks aligned on opposite sides of the interponents, their armatures extending inwardly from said electromagnets and providing a plurality of aligned stands to which the lower ends of the interponents are returnedby the springs, whereby armature control of the interponents is regained following armature unlatching. The armatures include elongated pivoted arms arranged in a chassis and having knifeedge portions pivotably mounted in 90 crotches formed along portions of the chassis. The arms are biased in the chassis so that the knife edges are urged into the crotch and the arms are freely pivotable in the crotch about the knife edges.

11 Claims, 6 Drawing Figures PATENTEDAPRN 1914 3.805695 SHEET u 0F 4 ARMATURE MOUNTING ASSEMBLY FOR A TELEPRINTER BACKGROUND OF THE INVENTION The present invention relates to signal responsive impact printers. More particularly, the invention relates to assemblies for controlling print hammers in impact printers having radial impellers.

In printers with which the present invention is concerned, what is characterized as line-at-a-time printing occurs on the fly, at high speeds, by reproducing images of a plurality of symbols simultaneously on a line in response to electrical signals. In one class of such printers, character dies or type may be conveyed on a continuously moving endless carrier past a lineal array of print hammers. To maximize printing speed in response to output capability of known automatic data transmission systems, the facility of the printing apparatus to respond to availability of data must be maximized. v

Ideally suited for developing impact forces in said class of printers, because of the high level of timing ac curacy for print hammer control, are impelling means of the type disclosed in U.S. Pat. No. 2,927,960, issued to W..P. Byrnes, Mar. 8, 1960. However, the mechanical inertia of the impelling means as well as of its print hammers limits the speed of printing response, in apparatus according to said patent, to a level which is incompatible with modern requirements, namely, an optimum rate for handling the output from a buffer storage, for example, between incoming data and a printing mechanism. My copending application Ser. No. 268,238, filed July 3, 1972 and-assigned to the assignee of the present application, discloses a printer which has the desirable features of said patent, but reduces the mechanical inertia. Said copending application is incorporated herein by reference.

But the maximization of printing speed cannot be at any expense. To the contrary, commercial considerations dictate that improved printing speeds be available at minimum costs, in a product of good quality for producing acceptable copy.

The thrustof improvements for minimizing costs can be directed to simplifying printer construction including minimizing the number of printer components and compacting printer size. This type of improvement produces an additional benefit of adapting high speed, signal responsive printers for portability and use in small places, such as motor vehicles. Heretofore, this need could not be met entirely by printers of the type of said patented printer because of their relatively large size, which in part resulted from the arrangement, in a single array, of control means for armatures which coacted with impellers for operating the print hammers.

It is an object of the present invention to provide a novel impact printer.

It is another object of the invention to provide a compact line-at-a-time impact printer.

It is a further object of the invention to simplify construction and minimize time of assembly of an impact, line-at-a-time printer having radial impellers for controlling an array of print hammers.

SUMMARY OF THE INVENTION The foregoing, and other objects of the invention which will become apparent from the ensuing detailed description, are attained in an impact printer having a lineal array of print hammers. They are responsive, respectively, to electromagnetically controlled armatures through the agency of interponents. The armatures are disposed in opposedbanks and have inner portions aligned, each with the other, for controlling of each of the hammers by selectively elevating an interponent into the path of arms on an impeller, for transferring impeller energy to such hammer. I

In particular, the invention relates to an improved armature-mounting assembly for such a printer, wherein the armatures include a set of pivoted arms arranged generally horizontally in a chassis of the printer. The chassis includes a vertical plate assembly defining a horizontal sharpcrotch of approximately along the lower edge thereof. Each armature arm is formed with a portion along its upper surface defining a horizontal knife edge, and the arms are mounted in the chassis so that the knife edges of all arms in the row are received in the crotch at spaced intervals along the length of the plate assembly. Means are further provided for biasing the arms in the chassis so that the knife edges are urged into the crotch and the arms are freely pivotable in the crotch about the knife edge.

away and parts omitted for the purpose of illustration;

FIG. 2 is a vertical sectional view of said printer according to the line 2-2 of FIG. 1;

FIG. 3 is a horizontal sectional view according to the line 33 of FIG. 2, parts broken out and parts omitted for the purpose of illustration;

FIG. 4 is a vertical sectional view of the printer according to the line 44 of FIG. 2, parts being omitted and parts broken out for the purpose of illustration;

FIG. 5 is a vertical sectional view of a subassembly of the printer, showing the printer chassis with magnetic cores mounted, the view being in the same plane as the plane of FIG. 2; and

FIG. 6 is an enlarged detailed view in a vertical plane of an armature assembly.

DETAILED DESCRIPTION OF THE INVENTION General Arrangement of Printer Referring now to FIG. 1 of the drawings, the impact printer shown is generally designated 10. It has a pair of spaced apart pulleys 12and 14 about which an endless carrier 16 is trained for translocating a plurality of pallets 18 by movement in a circuitous path. A plurality of dies 17 (FIG. 2) are carried on the front faces of the pallets. The pallets, exceptfor possibly the terminal pallets in a font, are uniformly'dimensioned and uniformly and equally spaced apart axially of the carrier. When dies 17 comprise alphanumeric characters, two or more successive fonts axially of carrier 16 may enable longer line output.

Carrier 16 and pallets 18, together with attendant elements (omitted from the drawings) may be substantially as shown and described in the copending application of Francis E. Huntoon and James F. Kearney, Ser. No. 208,198, filed Dec. 15, 1971, and assigned to the assignee of the present application, now U.S. Pat. No. 3,742,828, issued July 3, 1973. In accordance with said last named copending application, which is incorporated herein by reference, the plane in which parallel axes of pulleys 12 and 14 are disposed and the vertical section 20 of web 22 on which printing is about to occur are orthogonally disposed. Such arrangement generates a loop in the carrier with an upper or printing course 21 and a lower or return course 23 which are disposed in a plane which is substantially parallel to web section 20.

In the exemplary printer l0, pulley 12 isan idler sheave while pulley 14 is a drive sheave secured to a shaft 24. Driving torque continuously is transmitted to said shaft from an operating prime mover means,

e n s own a a i qtq xih 'Ql a r tr is ,trained about a plurality of ribbon guides 38 which are spaced apart such that the ribbon assumes a generally rectangular configuration in a horizontal plane. Opposed end portions of .the ribbon are'securedto a pair of adjoining ribbon spools 40 and 42 which-alter nately function for ribbon supply and accumulation. They alternately are driven in opposite angular direc tio ns,by. a spool control mechanism 44, the details of construction of which form no part of the present invention. Mechanism 44 is connected to motor 26 through a pulley wheel 46, disposed in a common plane with spools and 42. It is secured on an end portion 47 of shaft 24 for driving the spool control mechanism through a pulley belt 48. g

I A clutch ,50, which may be conventional, is mounted for releasably securing a split shaft section 52 to the shaft 24 from which said section extends axially. Selecthe actuation of the clutch may be effected through logic (not shown) which may be conventional and the details of construction of which form no part of the invention. Thereupon, operating means, being a drive train generally designated 54, advances web 22, in the direction shown by arrow 56,a line-at-a-time. Such advancement results from incremental rotation of a worm gear 58 for driving a pulley belt 60 intermittently angularly to move a meshing gear 59 and a cylindrical roller 62. Roller 62 is disposed transversely of and adjacent to the path of web movement for frictionally engaging web 22 and incooperation with other components (not shown), intermittedly drawing said web from its supply source (not shown) about a guiding cylinder 64, as said web is advanced.

lmpelling means comprises an-array of radially symmetrical impellers' 66 (only representative ones of which are shown in FIG. 1). The impelling means herein are substantially as shown and described in my aforesaid copending application Ser. No. 268,238 and in my application Ser. No. 268,236, also filed July 3, I972, and assigned to said assignee. Said last application is also incorporated herein by reference.

Accordingly, each impeller is comprised of a plurality of radial, equiangularly spaced arms or impelling elements 68, (FIG. 2), the impellers being concentrically secured to shaft 30 for rotation therewith in the direction shown by arrow 70 in the exemplary embodiment. The impellers are axially or horizontally spaced such that each is disposed in substantially horizontal alignment with a printing station on an imaginary line extending horizontally across web section 20. A plurality of circular shims 72 (FIGS. 2 and 4) are disposed between impellers 66 and define aplurality of-horizontally aligned annular chambers 74 as more particularly defined in said application Ser. No. 268,238.

Impacter means for printing comprise a plurality of equally spaced apart print hammers 76 (only some of which are shown in FIG. 1) disposed behind back face 78 (FIG. 2) of 'websection 20. The impacter means herein may be s ubstantially as shown and described in said copending application Ser. Nos. 268,236 and 268,238 as well as in application Ser. No. 268,237 filed July 3, 1972, which is incorporated herein by refer- 'ence. Accordingly, each hammer is aligned with the others in a horizontal array parallel to the alignment of impellers 66. Each hammer also is aligned with, though spaced from, and disposed out of the path of movement of an associated impeller by which it can be selectively driven in a lineal path,'perpendicularly to web section 20, between a normal or non-printing position (FIG. 1) and a printing position (not shown) moved to the right in FIG. 2 against said back face 78 (FIG. 2).

The dies 17 on pallets 18 in course 21 and hammers 76 are disposed at a common horizontal level; and said pallets and their dies when translocated move in a path parallel to the hammer array for printing. Thereby, each pallet 18 and groups thereof can be moved successively into printing positions in horizontal alignment with successive hammers 76 and groups thereof. The force generated by each impeller 66 for urging web section 20, ribbon segment 32 and any aligned dies 17 into contact is of sufficient magnitude for printing by forming an image of each such die on web face 36. In the exemplary embodiment of the invention herein, the hammers are associated with and reciprocatively arranged in the chassis or framework 29 by means and in the manner disclosed in said copending application Ser. No. 268,238.

A horizontal bumper, in the form of a rod 80 (FIGS. 1 and 2), is disposed parallel to shaft 30 has opposed ends secured in the chassis side walls 28. Said rod extends through horizontally aligned slots 82 in the hammers 76 for limiting horizontal hammer movement.

A leaf spring 84 (FIGS. 1 and 2) of general vertical orientation and associated with each hammer 76, is included in hammer driving means. The lower end portion of allof springs 84 are integrally fashioned with a horizontal front wear'plate 83 which is rigidly secured to a front chassis plate 86. An upper end portion of each spring 84 is engaged in a downwardly opening slot 88 in the printing head 77'of each hammer 76. Each spring 84 has a slightly tensioned condition (FIG. 2) during which its hammer is in its rearward or most remote non-printing position, and a most tensioned condition (not shown) during printing for urging or restoring its hammer to non-printing position.

Each impeller 66 is-adapted to move a printingly associated and aligned hammer 76 through the agency of an interponent 90. In the preferred embodiment of the invention, printing is effected and the assemblies of the interponents as well as the other parts of printer 10, including means for controlling and liberating the interponents are, as shown and described in said application Ser. No. 268,238. In accordance therewith, the interponents are disposed in general horizontal alignment and each has: (I) a first or upper position in which it is in a projected condition, with its upper free end portion disposed in the path of movement of associated impeller arms 68 for transmitting force from its impeller 66 to an aligned hammer 76 in consequence of which printing occurs, and (2) a lower, non-printing, or second position in which said interponent has been lowered and is removed from the impeller path as shown in FIG. 2.

As shown and described in said last named application, each interponent 90 intermittently is controlled by an assembly comprised of a magnetically latchable armature 92 and an electromagnet 94 (FIG. 2). Any suitable logic, (not shown and forming no part of the present invention) which may be conventional, may be employed for energizing selected electromagnets 94. In consequence of energization of any electromagnet its armature will be rocked, magnetomotively, against the restoring bias of its contractile spring 96, from its position shown (FIG. 2) upwardly to a latched position (not shown).

correspondingly, an affected interponent 90 will be thrust upwardly (from its FIG. 2 position) into its first position or projected condition (not shown) between a pair of adjoining impeller arms 68 against the lowering bias of an associated spring 98 (FIGS. 2 and 4) which becomes tensioned upon upward movement of its interponent. Ensuingly, an upwardly thrust interponent will be engaged by a circuitously travelling impeller arm 68 and rocked into engagement with an associated hammer 76 to effect momentum transfer and translation of impeller torque into a lineal force for printing. Both momentum transfer and restoration of each interponent 90 to its second position (FIG. 2) following momentum transfer, as well as the conditioning of interponents for repeat cycles are as shown and described in said last named copending application.

In the exemplary'printer 10, though the spacing between the centers of the hammers 76 need not be the same as the spacing between the centers of pallets 18 in course 21, the spacing of said hammers, as well as their dimensions, mode and sequence of operations, and printing with printer is as shown and described in said copending application Ser. Nos. 268,236 and 268,238. Moreover, adjustment of impact of the hammers preferably is as shown and described in said copending application Ser. No. 268,237. Accordingly, pallets 18 are mounted on the inner ends of shanks 100 (FIG. 2) whose outer ends are disposed against a backup bar 102; and said shanks are disposed in a horizontal plane and are removably mounted in carrier 16, extending transversely therethrough.

Magnet and Armature Assembly In the exemplary embodiment of this invention, each electromagnet 94 comprises a pair of electrically interconnected wire coils 104A and 104B of a windings member 104 (FIGS. 2 and 3). The coils, respectively, of each pair circumposed about legs 106A and 1068 of a pair thereof comprises a magnetic core 106. The cores, and accordingly their windings members, are uniformly spaced apart and disposed horizontally in a pair of straight parallel arrays, sets or banks 108 and 110. Bank 110 is aligned adjacent and parallel to the front chassis plate 86 and bank 108 is aligned along and parallel to a rear chassis plate 85 (FIGS. 2 and 3), which is parallel to front chassis plate 86. 5 Each core 106 has an upwardly projecting anchoring lug or shank 107 which is firmly secured in a respective one of a plurality of holes 112 (FIGS. 2 and 5) formed in a horizontal wall 114 of chassis 29. Said holes are aligned in said banks 108 and 110, the alignment of the holes in each set being parallel to the hole alignment in the other set and extending along and parallel to a respective one of the chassis plates 85 and 86. In accordance with the disclosure herein and as disclosed in at least one of my aforesaid copending applications, each 5 core 106 and its associated hole 1 12 in one of the banks 108 and 110, though equally spaced from adjoining core members and holes in the same bank, are offset horizontally-from the corresponding core and hole in the opposed bank by a distance equal to half the spacing between adjacent core members and their holes, as shown in FIG. 3.

A rear wear plate 116 (FIGS. 2 and 3) is secured to rear chassis plate 85, the latter being associated with bank 108. Wear plate 116 is parallel and corresponds to from wear plate 83 which is associated with bank 110. Each of the wear plates 83 and 116 has a depending overhang 118, (only one of which is shown in FIG. 6) which extends downwardly beyond lower end face 120 (FIGS. 5 and 6) of a corresponding one of chassis plates 85 and 86. This construction generates a horizontal sharp crotch 122 which extends longitudinally of each bank 108 and 110; and it facilitates the rocking movement of the armatures 92 half of which comprise bank 108 and the other half of which comprise bank 110. 1

A horizontally elongated guide or bracket 124 (FIGS. 2, 3, and 6), having a lower flange 125 (FIG. 6) and an upper flange 126, is associated with each of banks 108 and 110. One of said brackets is secured longitudinally of each of the wear plates 83 and 116. Each flange 125 has a lower set of downwardly opening guide slots 127 and an upper set of outwardly opening guide slots 128 disposed in a horizontal plane. An upper and a lower slot in each bracket comprise a slot couple associated with one of the armatures 92 and are vertically aligned; and each slot couple of each of banks 108 and 110, though equally spaced from adjoining slot couples in its bank, is offset horizontally from the corresponding slot couple in the opposed bracket 124 by a distance equal to half the spacing between adjacent slot couples.

Each armature 92 has an outer portion 129 (FIG. 6) with an upwardly projected extension 130. Each outer portion passes below the chassis 29 and outwardly therefrom through one of the slots 127 and is guidingly received in one of the slots 128. Each armature also has an inner portion 132 (FIGS. 2, 3, and 6) which terminates in a flat stand 134 (FIG. 4). The arrangement of the armatures in offset banks 108 and 110 is such that all of the stands 134 are disposed in general alignment, horizontally, with each armature being vertically aligned with an associated one of said impellers 66. A flat broad latching section 136 of magnetic material on each armature is disposed in alignment with the lower ends of a corresponding pair of core legs 106A and 106B to which such latching section is drawn upon energization of an associated windings member 104.

A flat 138 (FIG. 6) generated in each armature 92 is angularly disposed adjacent the inside surface of the overhang 118 of either wear plate 83 or 116 according to the bank 108 or 1 with which such armature is associated. A horizontal knife edge 140 which defines the upper limit of flat 138 is seated in a corresponding crotch 122 and facilitates pivotal movement of each armature between a first or printing condition (not shown) in which the latching section 136 of such armature is magnetically held against its core 106 and a second, non-printing or released condition (FIG. 2), in

which a corresponding spring 96 biases its armature 92 away from a magnetically attracted or latched position and against a bumper 141 (FIGS. 2 and 3). Each spring 96 (FIGS. 2 and 6) has an end anchored about one of the lugs 142 formed by slots 127 in flange 125 and an opposite end connected to an extension 144 from its corresponding armature 92.

A horizontally elongated channel 150 (FIGS. 2, 3, and 4), U-shaped in cross-section, has upper end portions of its opposed sides 152 and 154 suitably secured to the outside surfaces of a pair of spaced apart horizontally extending hanger plates 146 and 147.. Said last platesdepend from chassis wall 114 to which they are secured by a plurality of fasteners 143 (FIGS. 2 and 4).

Plates 146 and 147 generate a chamber 148 longitudinally of the alignment of impellers 66 and of interponents 90, said chamber 148 being coextensive with an elongated slot 149 in wall 114 through which the interponents extend upwardly toward said impellers. The closed end portion of channel 150 is spaced from the lower ends of said hanger plates 146 and 147 and closes chamber 148 from below.

Channel 150 is disposed medially of the electromagnets 94 of banks 108 and 110. Channel sides 152 and 154 are slotted, respectively, the slots 156 in side 152 and the slots 158 in side 154 being spaced apart in horizontal alignment. Stands 134 are disposed in the lower end portion of chamber 148 with the armatures in bank 108 passing through slots 158 and the armatures in bank 110 passing through slots 156 in channel side 152.

Bumper 141 extends alongthe bottom of channel 150 below and parallel to the general alignment of the stands 134. The bumper is held in a retainer 160 which is secured-along the bottom of the channel by means of a plurality of fasteners 164, (FIG. 2).

Operation of the exemplary embodiment of the printer is described in at least one of my aforesaid copending applications. The distinctive features of the present invention repose in the physical arrangement of the electromagnet and armature assembly, by reason of which the number of parts and their assembly can be minimized. Practical apparatus embodying the disclosure has been'simply and efficiently built, substantially reducing the cost of printer assembly over the cost of assembly of like devices, and in accordance with the following:

Initially the upper portion of the chassis 29 is cast. It comprises the wall 114, as a casting floor; the parallel vertical side walls 28, extending upwardly from wall 114; a rigidifying vertical web 170 (FIGS. 2 and 5), connected at its lower end to wall 114 and at its lateral ends to side walls 28; and a horizontal frame member 172 (FIG. 2) superposed relative to wall 1 14 and which defines a chamber 173 for hammers 76. Each wall 28 is fashioned with a hole 174 (FIG. 5) for receiving an annular bearing 176 in which one end of the shaft 30 is journaled. The holes 174 are fashioned such that their centers are coaxially aligned and define an axis 175 parallel to side walls 28 and about which shaft 30 rotates, when assembled.

' Next, using axis 175 as a line of reference, holes 112 are drilled in wall 114 such that their vertical axes are parallel to each other and perpendicular to the axis 175. The holes 112 associated with each of the banks 108 and have a uniform pitch of 0.200 inch in the practical embodiment of the invention, the holes 112 of each of said banks being offset 0.100 inch from the holes in the opposed bank. Following their fashioning, holes 112 are proportioned for receiving shanks 107 in a press fit such that the legs 106A and 1068 of each core are aligned perpendicularly to the axis 175.

Thereafter, parallel back and front chassis plates 85 and 86 are hung from wall 1 14 by a plurality of fasteners 178 (FIGS. 2 and 5). Then the assembly comprised of hanger plates 146 and 147 and the slotted channel are hung from wall 114 by fasteners 143.

Subsequently, again using axis as a reference, the lower ends 120 of the chassis plates 85 and 86 and the lower faces 180 (FIG. 5) on the legs 106A and 1068 are ground, in any known manner, into a single plane parallel to wall 114 and a preselected distance from axis 175.

Wear plates 83 and 116 are then secured to the chassis plates 85 and 86. Ensuingly, each pair of coils 104A and 1043 is merely mounted about corresponding core legs 106A and 106B and fixed thereto; and the coils are connected to logic (not shown) for energizing the electromagnets. Contemporaneously filed application of JamesF. Kearney, Ser. No. 290,192, assigned to the assignee of the present application, and which is incorporated herein by reference, describes and shows means for securing the coils to the cores and to said logic.

Next, shaft 30 with impellers 66 and hammers 76 are mounted in their proper positions. Thereafter the interponents 90 are placed in position. Lastly, the armatures 92 may be suitably mounted and the springs 96 connected.

As many modifications in the described construction could be, conceived, and as many widely different embodiments could be made without departing from the spirit and scope of the claims, it is intended that all matter contained in the accompanying specification shall be considered as illustrative only and not in a limiting sense.

I claim:

1. In combination with a teleprinter of the type having a chassis and a plurality of electromagnet armatures mounted in the chassis for operating a corresponding plurality of printing hammer mechanisms, the armatures including a set of elongated pivoted arms arranged generally horizontally in the chassis, an improved armature mounting assembly characterized by:

the chassis including a vertical plate assembly defining a horizontal sharp crotch of approximately 90 along a lower edge thereof;

each armature arm having a portion along its upper surface formed at an acute angle defining a horizontal knife edge;

means for mounting the arms in the chassis so that the knife edges of all arms in the row are received in the crotch at spaced intervals along the length of the plate assembly; and A means for biasing the arms in the chassis so that the knife edges are urged into the crotch and the arms are freely pivotable in the crotch about the knife edges.

2. An assembly as recited in claim 1, wherein:

the chassis includes a horizontal wall, to which the vertical plate assembly is secured, the vertical plate assembly including a vertical chassis plate fixed to one end of the horizontal wall and depending vertically therefrom, the lower edge of the chassis plate being flat and horizontal, and a vertical wear plate fixed to the outer surface of the chassis plate and extending a short distance downwardly therefrom so as to provide a depending overhang, the juncture at the lower edge of the chassis plate and the overhanging portion of the wear plate defining the horizontal crotch of the vertical plate assembly.

3. Apparatus as recited in claim 2, wherein:

an outer end of eacharm includes a curved portion tapering downwardly away from the knife edge, thence outwardly beneath the wear plate, and then upwardly generally parallel to the wear plate; and

the mounting means includes a guide bracket secured to the outer surface of the wear plate and having upper and lower guide slots therein, in which the outer portions of the arms are received for locating the arms in the slots and containing the pivoting movement of the arms to predetermined vertical planes.

4. Apparatus as recited in claim 3, wherein the biasing means of claim 6 includes a plurality of springs mounted between the lower ends of the guide bracket and a plurality of depending extensions formed along the lower surfaces of the arms.

5. Apparatus as recited in claim 3, further comprising an inner guide for the armatures comprising a flat channel plate secured to the horizontal wall and depending vertically therefrom, said plate having a plurality of elongated vertical slots therethrough, through which the inner ends of the armatures pass, the slots being aligned with the slots in the guide bracket so as to locate and guide the inner ends of the armatures, and being long enough vertically to allow the required pivoting movement of the armatures in a vertical plane.

6. Apparatus as recited in claim 5, wherein the channel plate forms part of a U-shaped channel in which the inner ends of the armatures are enclosed, the channel having a closed bottom wall, and wherein an elongated horizontal bumper is received in the bottom of the channel, on which the inner ends of the armatures normally rest and which sets the open or de-energized positions of the armatures.

7. Apparatus as recited in claim 6, further comprising a plurality of electromagnets for operating the armatures, the electromagnets including a plurality of vertically disposed core members secured to the horizontal wall at intervals along the length thereof, corresponding to the spacing of the armatures, the core members depending vertically from the horizontal wall and having flat lower surfaces precisely flush with the lower surface of the vertical chassis plate of claim 7, the core assemblies being located between the chassis plate and the channel plate of claim 10, and being arranged in a horizontal row parallel to both of those plates.

8. Apparatus as recited in claim 7, wherein there are provided two banks of armatures, two rows of coils, and two vertical plate assemblies, the vertical plate assemblies being secured to the front and rear ends of the horizontal wall, with the guide slots of a front plate being parallel to those of the rear plate, but offset half the distance between the slots of the rear plate, so that the armatures in a front row alternate in position with those of the rear row, the inner ends of the armatures in both rows projecting toward each other in interleaved parallel relationship and terminating at the center of the printer in a common vertical plane midway between the front and rear plate assemblies, the cores of the electromagnets being staggered in accordance with the positions of the armatures so that each core is centered directly above its corresponding armature.

9. A teleprinter including an armature assembly as recited in claim 8, and further comprising:

a plurality of interponents equal to the number of armatures, the interponents being disposed generally vertically in the channel in a single row corresponding to the spacing of characters to be printed, each interponent having a lower end aligned with and resting on the inner end of the corresponding armature;

means biasing the interponents downwardly against the ends of the armatures, the armatures being individually pivoted on energizing of the corresponding electromagnet to elevate the corresponding interponent a preset distance set by the vertical position of the magnet cores;

a plurality of impellers mounted above the deactivated position of the interponents, for striking an elevated interponent and moving the upper end horizontally; and

a plurality of print hammers mounted in a single horizontal row parallel to the armatures, interponents and impellers and above the horizontal wall of the chassis, and responsive to the movement of the interponents to print characters on a printing medium positioned adjacent to the outer ends of the hammers.

10. Apparatus as recited in claim 1, further comprismg:

an electromagnet for operating the armature, the

electromagnet including a vertically disposed mag net core member secured to the chassis and depending vertically therefrom, the core having a flat lower horizontal surface located in the same horizontal plane as the crotch and spaced therefrom so that the arm can pivot from a de-energized position where the arm is spaced from the core to an energized position where a magnetic portion of the arm engages the core and is stopped thereby in a horizontal position.

11. Apparatus as recited in claim 10, further comprising:

inner and outer guide plates mounted on the chassis, one on either side of the crotch and core, the guide plates having coplanar vertical slots for receiving portions of the arm and permitting pivoting movement of the arm in a predetermined vertical plane set by the plane of the slots.

Egg/ 5153339 T UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 5 95 Date; p il, 3, 1971;

' may 5." BABLER Zriventofls) It is carcified that errox appeamr in tha absve idemtified patent and that said Lettew Patent are hereby warranted as shown below:

In the Claims:

001mm 9 line 31 change "claim 6" to --claim 1 line 61- change "claim 7" t6 claim 2-=-;

line 633 change elaim 10" to --e1aim 5--.

Sigma d am said' this 19th day of November 197 McCiDY M6 GIBSON JR. c; M RS I LL DANN Attesizimg Officer I Conunls'sloner pf Patents 

1. In combination with a teleprinter of the type having a chassis and a plurality of electromagnet armatures mounted in the chassis for operating a corresponding plurality of printing hammer mechanisms, the armatures including a set of elongated pivoted arms arranged generally horizontally in the chassis, an improved armature mounting assembly characterized by: the chassis including a vertical plate assembly defining a horizontal sharp crotch of approximately 90* along a lower edge thereof; each armature arm having a portion along its upper surface formed at an acute angle defining a horizontal knife edge; means for mounting the arms in the chassis so that the knife edges of all arms in the row are received in the crotch at spaced intervals along the length of the plate assembly; and means for biasing the arms in the chassis so that the knife edges are urged into the crotch and the arms are freely pivotable in the crotch about the knife edges.
 2. An assembly as recited in claim 1, wherein: the chassis includes a horizontal wall, to which the vertical plate assembly is secured, the vertical plate assembly including a vertical chassis plate fixed to one end of the horizontal wall and depending vertically therefrom, the lower edge of the chassis plate being flat and horizontal, and a vertical wear plate fixed to the outer surface of the chassis plate and extending a short distance downwardly therefrom so as to provide a depending overhang, the juncture at the lower edge of the chassis plate and the overhanging portion of the wear plate defining the horizontal crotch of the vertical plate assembly.
 3. Apparatus as recited in claim 2, wherein: an outer end of each arm includes a curved portion tapering downwardly away from the knife edge, thence outwardly beneath the wear plate, and then upwardly generally parallel to the wear plate; and the mounting means includes a guide bracket secured to the outer surface of the wear plate and having upper and lower guide slots therein, in which the outer portions of the arms are received for locating the arms in the slots and containing the pivoting movement of the arms to predetermined vertical planes.
 4. Apparatus as recited in claim 3, wherein the biasing means of claim 6 includes a plurality of springs mounted between the lower ends of the guide bracket and a plurality of depending extensions formed along the lower surfaces of the arms.
 5. Apparatus as recited in claim 3, further comprising an inner guide for the armatures comprising a flat channel plate secured to the horizontal wall and depending vertically therefrom, said plate having a plurality of elongated vertical slots therethrough, through which the inner ends of the armatures pass, the slots being aligned with the slots in the guide bracket so as to locate and guide the inner ends of the armatures, and being long enough vertically to allow the required pivoting movement of the armatures in a vertical plane.
 6. Apparatus as recited in claim 5, wherein the channel plate forms part of a U-shaped channel in which the inner ends of the armatures are enclosed, the channel having a closed bottom wall, and wherein an elongated horizontal bumper is received in the bottom of the channel, on which the inner ends of the armatures normally rest and which sets the open or de-energized positions of the armatures.
 7. Apparatus as recited in claim 6, further comprising a plurality of electromagnets for operating the armatures, the electromagnets including a plurality of vertically disposed core members secured to the horizontal wall at intervals along the length thereof, corresponding to the spacing of the armatures, the core members depending vertically from the horizontal wall and having flat lower surfaces precisely flush with the lower surface of the vertical chassis plate of claim 7, the core asseMblies being located between the chassis plate and the channel plate of claim 10, and being arranged in a horizontal row parallel to both of those plates.
 8. Apparatus as recited in claim 7, wherein there are provided two banks of armatures, two rows of coils, and two vertical plate assemblies, the vertical plate assemblies being secured to the front and rear ends of the horizontal wall, with the guide slots of a front plate being parallel to those of the rear plate, but offset half the distance between the slots of the rear plate, so that the armatures in a front row alternate in position with those of the rear row, the inner ends of the armatures in both rows projecting toward each other in interleaved parallel relationship and terminating at the center of the printer in a common vertical plane midway between the front and rear plate assemblies, the cores of the electromagnets being staggered in accordance with the positions of the armatures so that each core is centered directly above its corresponding armature.
 9. A teleprinter including an armature assembly as recited in claim 8, and further comprising: a plurality of interponents equal to the number of armatures, the interponents being disposed generally vertically in the channel in a single row corresponding to the spacing of characters to be printed, each interponent having a lower end aligned with and resting on the inner end of the corresponding armature; means biasing the interponents downwardly against the ends of the armatures, the armatures being individually pivoted on energizing of the corresponding electromagnet to elevate the corresponding interponent a preset distance set by the vertical position of the magnet cores; a plurality of impellers mounted above the deactivated position of the interponents, for striking an elevated interponent and moving the upper end horizontally; and a plurality of print hammers mounted in a single horizontal row parallel to the armatures, interponents and impellers and above the horizontal wall of the chassis, and responsive to the movement of the interponents to print characters on a printing medium positioned adjacent to the outer ends of the hammers.
 10. Apparatus as recited in claim 1, further comprising: an electromagnet for operating the armature, the electromagnet including a vertically disposed magnet core member secured to the chassis and depending vertically therefrom, the core having a flat lower horizontal surface located in the same horizontal plane as the crotch and spaced therefrom so that the arm can pivot from a de-energized position where the arm is spaced from the core to an energized position where a magnetic portion of the arm engages the core and is stopped thereby in a horizontal position.
 11. Apparatus as recited in claim 10, further comprising: inner and outer guide plates mounted on the chassis, one on either side of the crotch and core, the guide plates having coplanar vertical slots for receiving portions of the arm and permitting pivoting movement of the arm in a predetermined vertical plane set by the plane of the slots. 